EVAP Emissions (small leak)

Hello Friends,
I woke up at a campsite in Grand Junction a week ago and my 2010 Tacoma wouldn't start. Turns out the fuel pump was dead and I had to get it towed and replaced. All went well, I have 150,000 miles on it, so I wasn't terribly surprised. The shop that replaced it told me the old pump was really dirty inside, I could imagine as I think every nook and cranny of my truck has been caked with Colorado and Utah dirt and mud hundreds of times.

3 days later my check engine light and traction control light come on. I end up taking it to the Toyota dealer, assuming something was up with the fuel pump install. I'll do a fair amount of work myself, but I don't really have the time or knowledge to deal with fuel line, evap emissions issues. They tell me it's a small leak in the EVAP emissions, and a smoke test is next as they checked the gas cap and that wasn't it. I take it home, tired of spending money at the moment, and open the hood, and the line directly below my finger, the one that goes into the cylindrical canister, then out the other side, was not connected. I can't imagine this happening on it's own, it has been unplugged, maybe when the fuel pump was replaced?

So, my simple question: does anyone know what this particular line is, the one I'm pointing to with the cylinder? I looked for engine diagrams and can't find anything. I reset the check engine lights and they have not come back on.

Thanks and sorry for being long-winded!

 

That's the EVAP purge line, the little canister is a filter, it goes to the EVAP purge valve, and if it was disconnected, it would cause an EVAP system code/leak.
The dealership may have pulled it off in preparation for smoke testing the system.

 

Since you said this happened not long after fuel pump being replaced. if the fuel pump seal is not sitting right or pinched it will cause that leak in the evap system. The best way to find the leak is smoke test the system. Smoke will find the smallest holes.
Like @Jeffs68 said that hose being loose in preparation for smoke test, that is the best place to hook up or at my work we hook up at the dust filter vent on the charcoal canister.that one will be difficult on a taco I think.
Look into renting a smoke machine to find the leak your self.

 

You said you reset the CEL and haven't seen it come back? Be patient and keep driving. if you still haven't seen anymore codes/cel in another week or two then you're good

 

Thanks all for the responses. Yes it seems most likely it was disconnected in preparation for the smoke test. I don't think it would be handled to replace the fuel pump, which was done a week before.

Anyways, I plugged it back in and reset the codes by unplugging/replugging the battery. No check engine lights yet. I'm stumped... but I'll ride it out and see if they come back on.

Thanks again!

 

It can take a week or two depending on driving conditions, fuel level, etc to give those leak monitors time to run

 

Well you nailed it! The saga continues... After a couple of days, the check engine light and EVAP code is back (small leak). The dealership did a smoke test and could not find the leak. Next step for me is take it back to the guys who replaced the fuel pump, I suppose, and see if they will warranty their repair and recheck the fuel pump install. However, if the dealership couldn't find the leak around the fuel pump, I'm not sure what is left to do?

 

could be a faulty monitoring unit reading incorrectly. but if this happen right after the fuel pump, i would say they didnt install the pump right or damaged the seal on install.

 

So the dealer didn't have any suggestions for how to continue? They just said "we didn't see any leaks"?

 

I'd try a new OEM gas cap before anything else.

 

This is what I'm thinking, too. Happening after the fuel pump is too coincidental.

After the smoke test yielded no results, the dealer said the next step is to drop the fuel tank and check the fuel pump install. The other shop that did the fuel pump swap is a Napa Auto Care Center, so my understanding is that it is under warranty, and I can take it to another Napa if the replacement was faulty and is causing these codes. I'll have to ask if this is a possibility.

Replaced the gas cap, unfortunately that wasn't it either.

Thanks everyone for your thoughts, truly appreciated.

 

This saga is ongoing. I got a third smoke test, they say it's the fuel pump o-ring. So I ordered the o-ring and am going to replace it on the fuel pump. Never accessed the fuel pump before, so I'll be searching around on the forum and elsewhere for some instruction. Any suggestions are appreciated. Thanks!

 

raising the bed is easier than dropping the tank according to a few in this thread

https://www.tacomaworld.com/threads/fuel-pump-replacement-is-there-an-easy-way.222075/

 

COLORADO11, i have similar problem, took it to dealership and could find anything wrong; did you resolve the problem..Thanks and God Bless